Overhead lifting systems, such as patient lift devices used in the health care industry, may generally comprise an overhead rail that guides a lift unit with an actuator, such as an electric motor or similar actuator, coupled to a mechanical lifting arm or cable lift system, such as a lifting strap. The lifting strap may be connected with a sling bar, to which a sling or other lifting accessory is connected. During use, a patient is positioned within the lifting accessory, and the lifting accessory is connected with the sling bar. The actuator of the lift unit controls raising and/or lowering of the patient that has been positioned within the lifting accessory.
Several components in a patient lift system are rated based upon a maximum working load (WL) that each component or sub-assembly can support. The working load rating is typically expressed in a weight value such as kilograms or pounds. By way of example only, a rail may be rated with a working load of “Extra Large” for a maximum load of 250 kg; a carrier or lift unit may be rated with a working load of “Large” for a maximum load of 150 kg; and a lifting accessory such as sling may be rated with a working load of “Medium” for a maximum load of 100 kg. Often, various components of a patient lift system may be interchanged—for instance, a variety of different sized slings exist, each having different working load ratings.
Accordingly, a need exists for encouraging operators of patient lift systems (such as nurses or other healthcare personnel) to use components with compatible working loads ratings, so as to properly use a patient lift system.